This invention relates to lubricant compositions and more particularly to lubricant compositions comprising oils of lubricating viscosity or greases thereof containing a minor multifunctional amount of an amine-sulfurized alkylphenol borate or an alkoxylated amine-sulfurized alkylphenol borate or mixtures thereof. The incorporation of the amine moiety provides good friction activity and possibly antirust characteristics; the sulfurized phenol group provides antiwear and antioxidant properties; and the boron ester groups provide high temperature stabilizing characteristics.
Borated amines, borated alkanolamines, borated ureas, amine salts of boron acids, chlorinated amine-boron complexes and aromatic amine-boron compounds are known in the prior art and described respectively in U.S. Pat. Nos. 3,449,362; 3,254,025; 2,999,074; 4,226,734; 3,076,835; 4,025,445; 3,014,870; 3,014,869; 3,007,873 and borated adducts of alkylamines and alkyldiamines are disclosed as friction reducing lubricant additives in U.S. Pat. No. 4,328,113.
The borates described in this application, however, provide in a single lubricant additive composition substantial antiwear, corrosion inhibiting, friction reducing, and high temperature stabilizing properties. These new compositions combine the beneficial properties imparted by sulfur, phenol and amine or alkoxylated amine and borate moieties within a single composition to provide a full range of benefits previously unavailable in a single additive compound. The additives compositions per se, as well as the lubricant or fuel compositions made therefrom are thus believed to be novel and unique. Accordingly, to the best of applicant's knowledge, these compositions have not been previously known or used as multifunctional-friction reducing additives in lubricant applications.